1. Stop taking shit.
This means stop compromising what you believe. Don't confuse this with #6. When someone 'tells' you to do something, and it conflicts with what you believe in, don't budge, even if it means 'getting in trouble', fired, etc. Even if your beliefs are dumb, it doesn't matter... they make you who you are, and if you bend them for anyone (even that hot girl you want) then you're nothing.
2. Learn to be realistic with your goals.
This means if you have trouble getting girls, don't expect to get an 8 or a 9. Infact, pick out a girl that you think is cute that you deserve, and pick her 'ugly' friend instead. Part of the reason guys have a hard time getting girls is because they don't have any experience. If you're too picky at first, you'll never get any experience.
This applies to other aspects of life. Find your boundaries, and set goals slightly out of reach, but not in the sky.
3. Set expectations for yourself, don't break them.
This doesn't mean 'I want to get ripped by June' or I want a hot girl by October'. Instead, set exceptions for yourself like 'I will go to the gym 4 days a week' (and don't attach a goal to it, just do it)
If you're struggling in life, it usually means you're not awesome. You know the guy on TV you see with the awesome car, girl, house, job, etc? You want that stuff right? Well you'll never get it unless you're awesome. You get awesome one step at a time. That means doing new things, learning new things. Learn to shoot a gun, learn a new language, take a fighting style of some kind, go workout.
4. Don't whine. Nobody gives a shit about your problems.
If you're bitching about how hard life is, you're doing it wrong. Life is only as hard as you make it. You can get a job, you can get in shape, you can get a girl... you just are too damn lazy to do it. Get off your ass and start the steps.
5. Do stuff. Nobody accomplished anything by siting at home doing nothing.
This goes back to point 3. Try to go out and do new things as often as you can, even if you're unsure of the result, you might surprise yourself. Go in with the attitude 'I'm broadening myself' and know that even if you don't enjoy what you're doing, you're more awesome for doing it. You now know more than you did an hour ago.
6. Say yes, don't say no.
When you are ASKED (not to be confused with told) to go out and do something, even if you think it's lame, do it. If you keep getting asked to go out and do lame stuff, find better friends. Every time you say no, it's a missed opportunity. I hate myself for everyone time I've said no to something.
Also, when you're out, if stuff is lame, and you're not enjoying yourself, or if something upsets you, stop. Realize that again you're gaining something from doing whatever you're doing, (even if it's just an experience or memory) and just do it. Then if you hate it, go home, and don't do it again.
7. When you are unsure, do the opposite of what you normally would.
When you question yourself, chances are it's because your brain knows something to be true, but your conscious doesn't want to accept it. This alone makes a HUGE difference. Go with your gut. When you're unsure, just decide upon what you normally would, then do the complete opposite.